1. Field of the Invention
This invention relates to an optical disk apparatus for reading data recorded on an optical disk such as a CD or DVD and reproducing the read data.
2. Description of the Related Art
Conventionally, an optical disk apparatus has generally become widespread which reads data recorded on an optical disk such as a CD or DVD and produces a reproduced signal of a voice or image based on the data thus read. The optical disk apparatus, as well known, is provided with a pickup head which irradiates the optical disk set in the apparatus body with a laser beam and detects the reflected beam as a read signal of the data recorded on the optical disk. The pickup head is movably attached in a radial direction of the optical disk set in the apparatus body. The optical disk apparatus controls a data reading position (where the optical disk is radiated with the laser beam and the reflected beam is detected) on the optical disk by moving the pickup head in the radial direction of the optical disk. In a conventional optical disk apparatus, when seek is carried out to move the data reading position on the optical disk from a present position to a remote position (hereinafter referred to as a target position), as described in JP-A-8-190771 and JP-A-2001-176090, the pickup head is moved in the radial direction of the optical disk at a predetermined moving speed according to the number of moving tracks.
Meanwhile, the optical disk apparatus provides variations in the moving speed of the pickup head permitting appropriate seek among apparatuses owing to variations in the performance of the components used. So in the method of presetting the moving speed of the pickup head during seek disclosed in JP-A-8-190771 and JP-A-2001-176090, taking into consideration the variations of the performance of the components used, the moving speed of the pickup head must be set for a speed lower to a certain extent than the maximum speed permitting the appropriate seek. Thus, the time taken for seek cannot be sufficiently shortened. In order to obviate such an inconvenience, JP-A-2002-329334 proposes a technique in which if seek has succeeded, the moving speed of the pickup head during the subsequent seek is incremented by a predetermined magnitude, and on the contrary, if the seek has failed, the moving speed of the pickup head during the subsequent seek is decremented by a predetermined magnitude.